Very low birthweight: dysregulated gestation versus evolutionary adaptation.

Area of Science:

• Evolutionary biology
• Reproductive health
• Perinatal medicine

Background:

• High rates of very low birthweight (VLBW) are often attributed to "dysregulated" gestation.
• An alternative perspective suggests natural selection conserves mechanisms for spontaneous abortion of pregnancies likely to result in frail infants.

Purpose of the Study:

• To propose that nonconscious decisional biology in gestation shares risk aversion preferences with conscious decisions.
• To investigate the hypothesis that very low birthweight (VLBW) incidence in male infants correlates with population-level financial risk aversion.

Main Methods:

• Time-series modeling was applied to monthly birth data (sex and weight) from the Swedish Medical Birth Registry (1993-2010).
• Population risk aversion was measured using the Micro Index of the Swedish Consumer Tendency Survey (MISCT).

Main Results:

• The incidence of VLBW among male infants in Sweden significantly correlated with the population's self-reported financial risk aversion.
• Increased VLBW odds in males were observed one month following heightened population risk aversion.

Conclusions:

• Persistently high rates of VLBW may result from a combination of medical interventions and natural selection mechanisms protecting reproductive fitness.
• Nonconscious biological decisions during gestation appear to mirror conscious financial risk-taking behaviors.